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Bad air quality in Norwegian cities – but solutions are possible

Foto: Stein Manø

Article from NILU’s Annual Magazine: Air quality in several major Norwegian cities is now so bad that it causes significant health problems, and if worst comes to worst, air quality may even be poorer in the coming years. “The good news is that there are measures that can improve air quality,” says NILU’s Leonor Tarrasón.

By Bjarne Røsjø

Leonor Tarrasón
Leonor Tarrasón, director of NILU’s Urban Environment and Industry Department. Photo: Ingar Næss

Everyone was talking about diesel cars and air quality in Norway’s major cities in 2011, especially after NILU scientist Dag Tønnesen presented a calculation showing that the road toll for diesel cars in Oslo would have to be increased by several hundred kroner if it was going to have any effect on air quality. “That event was a signal that it is necessary to take drastic action if we want to do something about pollution problems on the worst days in our major cities. But the most important thing Dag said was that it is entirely possible – and high time – to introduce systems that require those who pollute more to pay more than those who don’t pollute so much” says Tarrason, who is director of NILU’s Urban Environment and Industry division.

Nitrogen oxides cause health problems

Nitrogen oxides (NOX) is the collective term for nitrogen monoxide (NO) and nitrogen dioxide (NO2) gases, both formed during combustion in automobile engines, among other sources. NO2 in particular constitutes a health risk, because this pollutant results in increased morbidity and mortality from cardiovascular and lung diseases. Currently, Norwegian authorities allow much higher NOX emissions from diesel vehicles than from petrol vehicles, but beginning in 2014 there will be much stricter NOX requirements throughout the entire EEA.

The Norwegian Pollution Control regulations were tightened in 2010, including a provision that limited the annual average for airborne NO2 in inhabited areas to be below 40 micrograms per cubic meter (mg/m3). The regulation also set an hourly maximum for NO2 of 200 mg/m3 not to be exceeded more than 18 times over the course of a year (the 18-hour limit). NILU published figures in 2011 that showed that Oslo, Bergen, Trondheim and Stavanger all had annual mean values above 40 mg/m3 in 2010, and that both Oslo and Bergen had more than 150 individual episodes with exceedances of the 18-hour limit.

Could be worse

Calculations performed by NILU for the Norwegian Asthma and Allergy Association (NAAF) in 2011 showed that air quality in Oslo in 2025 could be even worse if the trend in passenger car sales continues as it is today. “We have concluded that it is a safe choice for both the climate and local air pollution to enhance tax policies and local initiatives that favour the use of smaller gasoline vehicles, hybrid and electric cars. In addition, it is obviously important to increase the focus on public transport, and to develop more effective systems for professional transport and light duty vehicles. In Oslo, the small diesel vans and trucks that are used for transportation of goods are actually a bigger problem for public health than the heavy duty vehicles travelling across the major roads” says Tarrasón.

Dialogue with relevant authorities

In 2007 Norwegian tax laws were changed to make diesel cars more attractive, because they have lower emissions of the greenhouse gas CO2 than petrol or gasoline driven cars. In 2011, the Norwegian government presented a new proposal for changes in fuel taxes. This time, the proposal was presented after a process including a major meeting of relevant experts, involving NILU, the Norwegian Health Directorate, the Norwegian Climate and Pollution Agency, the Institute of Transport Economics, NAAF and local government representatives, who discussed these issues with the state secretaries of the ministries concerned. “It is very positive that scientific and technical experts and research groups were able to join in the discussion and provide quantified information, so that policy decisions could be based on best available knowledge” Tarrasón said.